Safety tool for removing snap rings



Aug' 23, 1962 P. G. sTUL-rz, JR 3,050,838

SAFETY TOOL FOR REMOVING SNAP RINGS Filed Aug. 18, 1959 "Tamm-.

INVENTOR "s Posy G. Stul'rz Jr.

BY WWWZQMWQ ATTORNEY United States Patent Olice 3,050,838 Patented Aug.28, 1962 The present invention relates to safety tool for removing snaprings and constitutes a special form of tool for removing the snap ringsfrom the valve bridge stems of hydraulic lash adjustens of dieselengines although the tool, in the form illustrated and disclosed herein,or in any modified form thereof, may be employed to safely remove snaprings in other environments once the snap ring has been expanded by aconventional form of expander tool.

The invention is a complementary tool to that disclosed in the copendingapplication of Phillips, and Stultz, Serial No. 768,871. See in thisconnection more particularly FIGURE 16 of said application Serial No.768,871 which shows the coil spring and its cap piece depressed by aclaw on the center toggle lever so that the snap ring is exposed forremoval vby a usual form of expander tool fitting in the gap between theends of the spring snap ring, which latter springs into a circulargroove in the bridge stem to retain the cap and the coil spring inplace.

The problem has been that, when the expander tool expands the resilientsnap ring, the latter is thereby put under high elastic tension and thesnap ring often escapes from` the tool and will fly in any unpredictabledirection, often injuring eyes or inflicting injury on the operator orbystanders. `It is therefore an object of the invention to provide atool for removing snap rings in the expanded and tensioned conditionthereof which involves a safety factor in that the snap ring is madecaptive by the tool incident to its release from the part in which itnormally seats and to this end the tool comprises complemental fulcrurnand toe so positioned relatively to one another that in the act ofprying the snap ring from the groove or from the part normally carryingthe same such snap ring will be entrained by the fulcrum and heldagainst escape while it is entirely free to contract to its normalconstricted dimension or in other words to its unsprung conditionwhereby with perfect safety the same may be then removed from the tool.

The improved safety tool of this invention does not take the place ofthe expander tool but supplements the action thereof.

A further object of the invention is to accomplish the foregoing endsand purposes by an extremely simple form of mechanical tool having afacile application to the work and the mechanically simple and easymovement in the act of removing the snap ring.

With the foregoing and other objects in View, the invention will be morefully described hereinafter, and will be more particularly pointed outin the claims appended hereto.

In the drawings, wherein like symbols refer to like or correspondingparts throughout the several views:

FIGURE l is a fragmentary side elevational view corresponding generallyto FIGURE 1:6 of the prior application Serial No. 768,871 aforesaidshowing the initial position of application of the improved tool to thesnap ring of the bridge stem.

FIGURE 2 is a similar view showing the tool moved to an intermediateposition seating the fulcrurn and in position genenally to admit of theapplication of the expander tool to expand the snap ring.

FIGURE 3 is a similar view showing a third position of the leverincident to downward thrust upon its handle with the consequent liftingof one side of the expanded snap ring.

yFIGURE 4 is a bottom plan View of a form of tool constructed inaccordance with the present invention.

Referring more particularly to the drawings, 10 designates a bar leverhaving a shank 1t)a angularly disposed with respect thereto extendingoff one end of the bar 10 and having a curved or other form of handle 11formed at its other end.

The bar 10 or its shank 10a carries la foot 1-2 at the end opposite thehandle 11 which foot extends generally in a direction normal to theplane lof the shank 10B. At its lower free end the foot 12 carries anangle toe 13 which has a laterally curved free edge 13EL (FIGURE 4) forc011- forl ing generally to the -surface of the bridge stem 16.

T he shank lila on. its underside carries a fulcrum 14 which in the formof tool disclosed herein isY generally in the form of a ball or sphere.This fulcrum 14 is spaced from the toe A13.

The bridge stem 16 is hollow and at its upper end is provided with aharing 'mouth 17 providing a seat for the ball 14. The stem 16 is formedwith an external circular groove 118 in which is adapted to seat a splitresilient snap ring E. A coil spring 20 surrounds the stem 16 and urgesa cap '21 upwardly normally abutting the snap ring 19. At 22 isrepresented the cla-w of an instrument for depressing the cap 21 andcompressing the coil spring 20, such claw being a part of the tool ofthe copending application Serial No. 768,871 aforesaid.

In the operation of the device, the claw 22 is made to force the cap 21downwardly and to compress the spring Ztl so as to expose the snap ringfor the removal movement.

The safety tool of this invention is then initially applied in theposition of FIGURE l with t-he toe 13 entered beneath the snap ring 19at one side and with the ball fulcrum 14 poised above the iiaring mouth17 and with the bar lever 16 in the diagonal position shown.

The bar lever y1l? is thereupon rocked down to the left to settle theball 14 upon the mouth seat 17, the parts assuming the position ofFIGURE 2; whereupon the expander tool is applied to the split ends ofthe snap ring 19 and when the snap ring is expanded clear of the groovev155, the handle 11 is depressed further to the position of FGURE 3,rocking on the ball 14 and elevating the toe 13 beneath the snap ring.The snap ring is accordingly lifted olf the stem 16 and into a positionsurrounding the ball 14 which coniines the snap ring 19 throughout theentire 360 and thus prevents the snap ring from flying oit in anydirection. The bar 10 will prevent escape of the snap ring 19 lupwardlyand the foot 12 and toe 13 will also contribute tov/ard coniining thesnap ring 19. 'Ihe diameter of the ball 14 will preferably be onlyslightly less than the diameter of the snap ring in its contractedcondition. rllhis diameter of the ball 14 is of counse in excess of thewidth of the gap between the split ends of the snap ring 19 in theexpanded condition thereof. In the position of FIGURE 3, it will benoted that the ball fulcrum 14 extends down from the shank 10a of thebar lever 1@ to a lower point than the toe 13. The relationshipbetween'the ball fulcrum 14 and the toe 13 is such that the toe leversthe snap ring 19 onto the ball fulcrum 14 immediately the snap ring isforced above the upper end of the stem 16 so that the snap ring 19 hasno opportunity for escape in its sprung condition. There is no place forthe snap ring to go except about the ball fulcrum 14 where it is free toimmediately contract in a restrained and restricted area.

As the snap ring 19 comes off the stem 16 the safety tool may begradually turned over so that ultimately the snap ring 19 will rest on.the shank 10a of the bar while the snap ring still surrounds the ball14. The snap ring in its unsprung condition can thereupon be easilylifted olf the ball with perfect safety.

As shown more particularly in FIGURE 2, the ball or sphere fulcrum 14has an outer hemisphere by Vwhich is meant more remote from the leverportion 10au and an inner hemisphere by which is lmeant Vadjacent thelevery portion-10a carrying the ballfulcrum 14. 11n FIGURE 2,

which is theV position of initial placement of the tool, the Y twoVhemispheres may be also characterized as'lower and spherical surfacetapering upwardly from the central plane towardl the lever part'lt)2vand thus forms walls which are progressively diminishing in crosssection from the central plane to the attachment to the lever part 19a.lt is'this upper hemisphere that functions primarily to entrap and makecaptive the snap ring 19 when it is lifted olf the end of the stem 16 bythe angle toe 13. -It must be remembered that when the snap ring 19 islifted out of its groove 18, it is expanded and under stress. Whilethese snap rings are small they must be of strong constictive Yetort,consequently a substantial force is necessary to :pry the split endsapart and even on fractional opening at the split ends the snap ringacquires tremendous reactive stress which is the property that causesthese snap rings to suddenly and with great momentum release themselveswith inurious effect to operators and bystanders. As soon as the ringcomes oi the upper end of the steam 16, it will snap back to nnsprungform and in doing so its inner wall will contact the upwardly taperingpart-spherical wall of the upper or inner hemisphere and the ring willordinarily vibrate rapidly around and laterally of this upper hemispherebeing deflected upwardly thereby toward the lever'part 10a and beingmade captive thereby and prevented from re-assuming any positionoutwardl of the stem 16. l Y

Although I have disclosed herein the invention known to me at this time,I reserve the right to all such modifications and changes as maycomerwithinY the scope of the following claims.

What is claimed is: Y

1. For use with a stem having a flaring mouth at a free end thereof anda seat close to the free end for a split resilient snap ring, a safetytool for removing the snap ring and making the snap ring captive to thetool comprising a lever, aY ring-engaging member at an end portion ofthe lever for engaging the ring and shifting the same from its seat andoi the end of the stem when the ring is expanded, and a fulcrum memberon the lever spaced from the ringengaging member of ball form having acentral equatorial plane spaced from and substantially parallel to thelever portion carrying the fulcrum member and dividing the ball fulcruminto inner and outer hemispheres, said outer best form of the ihemisphere adapted to enter and rock on the flaring mouth with the innerhemisphere having a part-'spherical wall diminishing in cross sectionprogressively from the central plane toward the lever for guiding theVfreed'and con-V tracting snap ring to the diminishing cross section ofthe inner `hemisphere and toward, the lever', the diameter of the ballfulcrum being slightly less than the internal diameter of the snap ringin its contracted condition and greater than the Width of the gapbetween the split ends of the snap ring in the expanded condition ofthesnap ring.

v2. For use with a stem having a flaring mouth at a free end thereof and=a seat close to the free end for a split resilient snap ring, a safetytool for removing the snap ring and making the snap ring captive to thetool corn-` (c) a fulcrum member on the -lever spaced from thering-engaging member having at its outer portion remote from the lever afulcrum adapted to enter and rock on the ilaring mouth,

(d said fulcrum member also having adjacent the lever a part-sphericalportion having its greatest crosssection spaced from and substantiallyVparallel tothe Y lever portion carrying the fulcrum member,

(e) said part-spherical portion diminishing in crosssectionprogressively from said greatest cross-section toward the lever forguiding the freed and contracting snap ring to the diminishingcross-section and toward the lever, Y

(f) said greatest cross-section being slightly less than the internaldiameter of the snap ring in its contracted condition and greater thanthe width ofthe gap between the split ends of the snap ringfin theexpanded condition of the snap ring,

(g) said ring-engaging member comprising afoot and Y (h) a toe on thefoot, (i) said foot depending from the lever at a point displacedsubstantially from the fulcrum member toV References Cited in the le ofthis patent UNITED STATES PATENTS 2,728,250 Robert Dec. 27, 1955 RanseenApr. 27, 1948'

